My mother insists that I should put some oil on my baby’s back and chest before bath time. She said it will help baby not to get “cold”. Do you practice the same thing?

Usually, I apply Ruyi oil on my baby after her bath, not before. The bath water will keep your baby warm, so I don't see the need of applying oil before bath time. After drying her off with a towel, I apply Ruyi oil and rub it between my palms until it gets warm and rub her tummy, back and soles of feet with it. It helps her to sleep better and release gas in her tummy. It's readily available from medical halls and inexpensive.